1. Field of the Invention
The invention relates in general to a light-emitting device and an electronic device using the same, and more particularly to a light-emitting device with multi-faceted light guiding effect and an electronic device using the same.
2. Description of the Related Art
For enabling users to operate electronic devices, such as mobile phone, PDA, or digital camera, in a dark environment or at nighttime, the electronic devices are normally equipped with light emitting elements. Light emitting diode (LED) or organic light emitting diode (OLED), having the advantages of small size, no radiation, low power consumption and fast response, has been widely used in the illumination of many electronic devices.
Take LED as an example of light emitting source for the keypad of a mobile phone. Normally, a number of LEDs are disposed on the circuit board of the mobile phone. The LEDs are disposed under the keypad of the mobile phone, and a light-guiding plate is disposed between the LEDs and the keypad. The light emitted from the LEDs is projected onto the keypad through the light-guiding plate. As each LED has specific lighting range and emission intensity, in order to assure that each press key on the keypad has sufficient illumination, several LEDs are used to meet the requirement. It requires not only more manufacturing cost but also consumes more power. Moreover, the LEDs and the light-guiding plate both have certain thickness. When the LEDs and the light-guiding plate are disposed between the circuit board and the keypad of the mobile phone, the overall thickness of the mobile phone will be increased.